Why incomplete subscript/superscript alphabet ?

[a.lukyanov]

I think that the right thing to do would be to create several new 
control/formatting characters, like this:

"previous character is superscript"
"previous character is subscript"
"previous character is small caps (for use in phonetic transcription only)"
"previous character is mathematical blackletter"
etc

Then people will be able to apply this features on any character as long 
as their font supports it.